Method and means for supervising railroads



July 29, 1930. G. H. SCHIEFERSTEIN METHOD MEANS FOR SUPERVISING RAILROAD'S Filed Aug. 20. 1927 Fig.1.

Fig.3.

Patented July 29, 1930 PATENT OFFICE enone HEINRICH sonrnrnnsrnrn, or isnnnin-cnannorrnnnune, GERMANY METHOD AND MEANS FOR snr'nnvrsine narnnoans Application filed August 20, 1927,1Seria1 No. 214,346, and in Germany August 20, 1926.

This invention relates to a method of super vising the condition of'railway tracks;

As is evidenced by the frequency of ac' cidents and collisions, the supervision of 5 railway tracks asnow carried out with known .means, is imperfect. i c

The subject of the present invention is a method of testing railway tracks from a distance, by the aid. of mechanical oscillations induced in therails themselves.

Consideredirom the oscillometric standpoint, lines of rail always: possess elasticity and mass in such degree that they-may generally be regarded as excellent conductors of 5oscillations of any order of dimensions; It,

therefore, a line of rall be excited with, say

30000 oscillations perminute bya mechanical system oscillating with that frequency, the line of rail in. question will transmit this oscillation through a longer or shorter distance, depending on the input of energy, each fishplatejoint, however, exerting a certain damping sheet on the oscillation transmitted. It may therefore be assumed that, inthe case of lines'of rail of normal character, a perfectly definite proportion of the input energy will bedestroyed by damping, per

kilometer (or 10 kilometers has once been determined by repeated measurem'ents, which are easily carried out, it may naturally be concluded, when fresh tests res veal substantially increased losses,that the rail joints in the section under examination have correspond ngly deteriorated, either in general, or in some partlcular spot; or, if

the emitted oscillations disappear completely,

that-there is some break in the line of rail.

According to this novel perception, on

which the present invention is based, all that- 4o is necessary, in order to be able toform an estimate of'the mechanical condition. of a railway track,"is to'impart to the track, at any convenient point by known means, mechanical oscillations lying within the range of andibility, and to receive said oscillations ata distant point, whichniaybe, if desired, translated into electrlc'al energy, also by known means, such as a telephone, microphone, relays or recordlng instruments and to note the variations in-the intensityof the WVhen this value a distance,and its presence on the section desound or the amount of energy absorbed. The sensitiveness of the receiving device (which may be equipped with amplifiers of known type) on the one hand, and the pos sibility of employing, on the other, an energy the interveningsection, and secondly, a mani--- fest record at the receivlngstation, 1n the event, say, of a rupture inthe continuity of the line through the failure of even a single lishplate which can be detected in known manner by signals) should be directly evident, since the energy of excitation and the sensitiveness of the receiver can be maintained at constantvalue in eachcase, and the relatively lowdamping at each joint rises to infinity when the fishplate becomes detached. Itmay even be assumed, and can he tested with sufficient frequency in, the'case of joints at normal distances, that the detaching of a 7'5: fishplate (which is always a matter of several minutes) can be'clea rly followedand recognized in the acoustic receiver, so that at the moment danger arises suitable measures-can be imiriediately taken. i r

In the caseot short distances, the acoustic signals can bedetected with correspondingly simple means, and evenby means of headphones, in known manner;

It might be advantageous to check a sec tion with, for example, 30000 oscillations from A, and 40000 oscillations from B. Both oscillations can be diiierentiated by signalling means, or acoustically by sound filters, monotelephones'or other known devices.

Since the present arrangement reacts to acoustic excitation of the rail track, the sound due to a train travelling in the section in question must also bedeterminable in the receiving apparatus, such sound superimposing itself on the relatively high and pure sinusoidal note. Hence the approximate position of the travelling train can also be estimated from termined.- e

The excitation of the mechanical oscillations may be efiected in known manner, both electrically, by means of a magnetic loosecoupling, and mechanically by the use of one of the known types of mechanical couplings (elastic coupling, inertia coupling, friction coupling, intermittent coupling).

In so far as possible, acoustic receivers are used, the range of oscillations employed may extend right through the acoustic scale, but

it is also'po ssi-ble to operate With-oscillations" to which the ear is not directly sensitive, i. e. supersonic.

When work is being carried out on the track, the mechanical oscillation continuously transmitted through the line. of rail can be utilized for directly supervising the work performed, especially the efliciency of the joints. can be detected, and the necessary ope-rations be arranged accordingly. 1 v

In order that the invention may be fully understood it will now be described with reference to the accompanying drawings, in which- Figure 1 represents the typical arrangement of a generator for initiating mechanical oscillations by mechanical means.

Fig. 2 shows a typical construction of the mechanical exciting member of such a generator.

Fig. 8 shows an arrangement of an apparatus for receiving the mechanical oscillations transmitted by a. line of rail.

In Fig. 1, 1 denotes a railway rail which is connected to the adjoining rail by' a fishplate 2. The excitation of the line of rail is eifected by setting a generator 6 (composed in known manner of an elastic member-4. rigidly comiected to a mass 5 capable of oscillating) in oscillation at high frequency and small amplitude, said oscillations being transmitted to the rails by the mass 3 to which the member or tube 4 is also rigidly connected. The frequency may be such as lies within the audible range appreciable by the human ear, or itmay be higher than such range, so that it can only be received or recorded by suitable receiving apparatus in known manner.

Fig. 2 represents a typical embodiment of the oscillation generator. Rotary unbalanced members 6 are rotated at a speed corresponding to the periodicity of the oscillatory sys tem 4,. 5, by means of a motor 14, through belt transmission gear 11', 12 and 13, and with the interposition of an elastic member such as a spring 8 which connects the driving and driven portions. The excentrically loaded or unbalanced wheels 6 cause their shaft section to vibrate, and this vibration is imparted to the mass 5 which-sets up vibration in the elastic or resilient member 4 thatrtransmite-vibrations to themass 3rigi'dly connected to the rails 1. The connecting member 4 is yielding to variation in amplitude between the In this case also, an oncoming train.

rails and the generator of the mechanical oscillations.

Figure 3 shown an arrangement for receiving the oscillations at a distant point. The mechanical oscillations imparted to the rail 1 are transmitted through the fishplate 2 to the adjoining rail, and thence to the next, and so on, and, as the result of the damping effect ofeach pair of lishplates, are weakened to a certain extent, which increases in proportion as the jointing is less effectively carried out.

A microphone 16, which translates the mechanical impulses into electrical impulses, is attached to the line ofrail by means of an angle bracket 15 and can also be loaded with a mass 17, enables a percentage of the oscillation energy to be received, translated into electrical energy, and transmitted through a conductor 18 to a telephone receiver 20, which may also. be provided with a local amplifier 19 of electrical current in known manner.

The receiving apparatus employed may be of any suitable type adapted to receive. minute electrical impulses, which will induce the person in charge to set the section of track out of operation; alternately, the receiv ng apparatus may be arranged to operate through relay devices in order to block the section in 2. A method of supervising the conditions of a "line of rails of a railway track, which comprises setting the line of rails inmechanical oscillation of high frequency and small amplitude, receiving said oscillations at a distant point of the-line of rail, and translating suchreceived oscillations into electric impulses ofau'dible frequency.

3. A method of supervising the conditions of a line of rails of a railway track, which comprises setting the line of rails in mechanical oscillation of high frequency and low amplitude, the amplitude of the oscillations being. reduced from one rail to another by the rail connections, receiving at a distant point mechanical oscillations, translating such mechanical oscillations into electrical impulses and amplifying said impulses.

4. Method as set forth in claim 1, in which the damping effect exerted by the individual rail connections or joints on the mechanical oscillations transmitted therethrough changes the audibility in accordance with the eificiency and condition of they connection or joint or of a number or all of the series ofjoints, and determines the condition of the line of rail, whereby supervision and control is enabled.

5. A method of supervising railway track, which comprises generating mechanical vibrations in a line of rail thereof at one'point of said line, and at a distant point of said line of rail listening to the sound produced by such vibrations, and therefrom determining the efliciency of the joints ofthe rails in the line of rail between the two points.

6. A device for supervising the condition of railway tracks, consisting of a generator of mechanical oscillations attached to a rail of the section under supervision, and one or more receivers for such oscillations connected to the line of rail at one or'more points remote from the generator for receiving the mechanical oscillations transmitted through the line of rail from the generator.

7 Mechanism for supervising the condition of railway track which comprises, a mass rigidly connected to a rail, a resilient memher rigidly connected to the mass, and means for setting the member in vibration, and means at a distant point of the rail toreceive the vibrations set up in the rail.

8. Mechanism for supervising the condition of railway track which comprises a mass rigidly connected to a rail of such track, a member connected at one end to said means and capable of oscillation, and means on the other end of said member to set it in oscillation and operating in resonance therewith, and means at a distant point of the line of rail to receive oscillations set up therein.

In testimony whereof I atfix my signature.

GEURG HEINRICH SCHIEFERSTEIN. 

